But at least two of those could come into contention for the reserve game against Villa at New Ferens Park.

Thirlwell and McCann are the two closest to returning to action.

If they play it would come as a huge boost to Peter Reid, who has seen his squad stretched in midfield of late because of the injuries.

With the midfield quartet of Thirlwell, McCann, Arca and Reyna on the sidelines, Reid has been forced to reshuffle and move Michael Gray from his more familiar left-back role to the right side of midfield.

Reid said: "We were without six players on Tuesday and for the likes of us it decimates you.

"We are not like the Arsenals and Manchester Uniteds who can field two teams. We had a lot of influential players out.

"Having said that, the players who have come in have done brilliantly for us.

"It would be a big bonus if we could get some of our players back for the Chelsea game.

"Without putting any pressure on, the reserves play on Monday and I am hoping there will be one, two or even three involved in that game."

Reid will be without another influential player at Stamford Bridge, where Sunderland will be looking for only their fourth away league win of the season but a repeat of last season's success.

Tuesday's goalscoring hero Jason McAteer will sit out the match through suspension after picking up his fifth yellow card of the season in last month's Tyne-Wear derby.